A method of producing a coherent multifilament yarn



June 2, 1970 J. A. BRISCOE 3,514,824

METHOD OF PRODUCING 'A COHERENT MULTIFILAM-ENT YARN Filed April 4, 1968 w 4 rain 5X5 United States Patent US. Cl. 2872.1 3 Claims ABSTRACT OF THE DISCLOSURE A bundle of substantially parallel, continuous filaments is subjected to the plucking action of a deflecting member which sets the filaments in vibration in such a manner that they become individually and collectively intertwined and entangled to produce an interlaced yarn.

The present invention relates to a method for the production of continuous multifilament yarns in which the filaments are interlaced or intermingled to provide a coherent structure.

Many methods have been proposed for producing coherent yarns which rely for example on the turbulence effects created by air jets to provide the necessary interlacing of the filaments. However, the volume of air used in any particular process of this type is usually very large and consequently the cost of the air is an expensive item which is reflected in the cost of the final interlaced product.

An object of the present invention is to provide a cheap and simple mechanical method for producing such co herent yarns.

According to the present invention, a method of producing a continuous, multifilament, coherent yarn, comprises subjecting a moving bundle of substantially parallel filaments, maintained under tension, to the action of a deflecting member which intermittently deflects the bundle of filaments from its path of travel, and randomly releasing the filaments from the deflecting member after each deflection whereby the filaments are caused to vibrate and become individually and collectively intertwined and entangled thus forming a coherent structure.

The invention also includes coherent yarns made by the method.

By the term substantially parallel is meant that the filaments forming the bundle are untwisted or only have a spinning twist, that is, as might be introduced by overend unwinding from a bobbin.

The deflection of the yarn may be effected either by: (a) moving the deflecting member across the path of the moving filamentary bundle or (b) by moving the filamentary bundle to and fro transversely to its mean path of travel across a stationary deflecting member.

In the former case, the deflecting member may comprise a pin or peg for example, which pin is mounted on a carrier which is movable to bring the pin into intermittent engagement with the bundle of filaments. Preferably, a plurality of spaced apart pins are mounted on a rotatable plate or wheel. The plate is arranged in relation to the moving bundle of filments in such a manner that rotation of the plate causes the pins to be moved across the path of the filamentary bundle. Each pin, in turn, engages and deflects the bundle of filaments from its path of travel.

When the plate is mounted substantially normally to the path, each pin is mounted obliquely on the plate so that it presents a sloping side to the bundle of filaments as it engages the bundle. When the plate is arranged 3,514,824 Patented June 2, 1970 obliquely to the path, the pins may be mounted normally to the plate. As the deflection of the bundle is increased the filaments ride up the sloping side of the pin and fall from the free end of the pin. Since the bundle is composed of a plurality of filaments, these filaments become randomly disengaged from the pin singly and in small groups and, because of the tension therein, are caused to vibrate. By the time all the filaments in that length of the bundle affected by the pin have stopped vibrating they are found to be intermingled, and the bundle has advanced along its path of travel before the next pin begins to deflect the filaments of the bundle.

It has been found that the length or time of contact of the filamentary bundle with a pin is an important factor governing the amount of coherency achieved. If the release of the filaments from a pin is delayed, that is the contact time is prolonged, a desirable intertwining and entangling of the filaments occurs when they are finally released and consequently a more coherent product is obtained. Such delay in releasing the filaments may be conveniently achieved by providing grooves in, or protuberances on, the pin in the region of its free end.

The bundle of filaments is preferably passed over two guides, and the bundle of filaments is subjected to the action of the deflecting member as it spans the guides. The first of the two guides is preferably situated at a distance of about one to four inches from where the bundle is engaged by the pins.

Other examples of movable deflecting members are pins mounted on a continuous band and a toothed wheel with teeth of suitable profiles.

The movable deflector members may conveniently be mounted for operation on a standard type of draw frame. The movable deflector member may be mounted, for example, on an idler roll, or a relax roll, or a separator roll, of a draw frame, or may be separately driven.

Alternatively, a stationary deflector member may be used across which the bundle of filaments is caused to move to and fro transversely to its mean path of travel. In this embodiment of the invention the bundle of filaments is moved to and fro over the grooved surface of a stationary pin, the to and fro movement of the bundle being effected by a rotating oscillator disc fitted with two or four pegs.

In using the method of the present invention to produce coherent yarns the tension in the bundle of filaments, which is subjected to the action of the deflecting member(s), is another factor to be considered since for a given deflection the degree of intermingling of the filaments increases with increased tension. At high tension levels there may be a tendency for some of the filaments to be overstrained by the action of the deflecting member so that they become permanently stretched and undesirable loops are formed in the yarn. Thus for a given bundle of filaments the maximum tension and amount of deflection which can be applied thereto, in order to achieve the highest degree of interlacing and avoid the formation of loops and/or breakages, is determined by the physical properties of the filaments. In order to guard against the possibility of filament damage it may be desirable to have a yarn guide so situated as to limit the deflection of the bundle of filaments.

An embodiment of an apparatus for carrying out the method of the present invention will be described by way of example with reference to the accompanying drawing, in perspective and wherein parts have been omitted for convenience, in which a deflecting member is mounted on the draw roll of a draw frame.

An undrawn bundle of denier, 30 polyethylene terephthalate filaments was taken from a supply, and the substantially parallel filaments were drawn. The drawing was carried out by passing the filaments round a feed roll and over a heated plate (both not shown), before passing. through a yarn guide 10 and then making several turns around a draw roll 12 and a separator roll 14. A circular plate 16 was fixedly mounted, concentrically, on the draw roll 12. A plurality of cylindrical pins 18 was carried by the plate 16, the pins being equally spaced apart along the peripheral marginal portion of one side of the plate as shown. Each pin 18 was mounted obliquely to the said side of the plate 16.

In operation, the bundle of filaments passed from the yarn guide to the draw roll 12 and made several turns round the draw roll and the separator roll 14. The draw roll 12 and the plate 16 rotated in unison, in the direction of the arrow A, so that each pin 18 was brought, in turn, into engagement with the filaments 8 and deflected the length of the bundle spanning the guide 10 and the draw roll 12 from its path of travel (indicated by the broken line). Upon being released from each pin 18, the length of the filament bundle 8 between the guide 10 and the draw roll 12 was caused to vibrate, due to the tension in the filaments, such that the filaments became individually and collectively intertwined and entangled to produce a coherent yarn. The coherent yarn was passed from the draw roll 12 to a relax roll (not shown) and was then wound onto a bobbin.

A fixed yarn guide 20 was suitably positioned to guide the first turn of the coherent yarn on the draw roll 12 clear of the pins 18, so that no further intermingling treatment of the yarn would occur as it left the draw roll. However, the guide 20 may be removed if desired.

If it is desired that the interminglin'g should be done separately from the drawing of the yarn, the plate 16 may be mounted on the relax roll.

The invention will be further described by reference to the following examples.

In each of the examples to be described the coherency factor of the yarns processed according to the present invention was measured according to the following method:

A sample of yarn to be tested is removed clockwise overend from the drawn package and is pre-tensioned at grams before it passes to a feed roll having a surface speed of metres per minute. From the feed roll yarn is led round guides leading to a narrow matt-chromeplated groove at the end of which is disposed a ceramic rod over which the yarn is formed into a substantially flat ribbon. A spring-loaded needle, with a sharp steel or sapphire point, projects into the yarn immediately it leaves the ceramic rod guide. The needle projects a distance of 1 millimetre into the yarn. When entanglements in the yarn apply a force of 5.0 to 5.6 grams on the needle it is caused to be moved with the yarn to a point where it actuates a microswitch which causes a solenoid to retract the needle which then returns to its original position but does not yet penetrate the yarn. A set delay time of 130 milli-seconds after operation of the microswitch passes before the solenoid relases the needle, which reenters the yarn to repeat the cycle when a sufiicient force is exerted thereon by an entanglement. Each operation of the microswitch also actuates a counter. The yarn then passes over a second feed roll, having 0.5% increase in surface speed over the first feed roller, being it is wound up on a bobbin. The instrument automatically stops running after one minute and the counter reading is noted for that 20 metres of yarn. The coherency factor of the yarn is the number of counts/ 20 metres of the yarn.

EXAMPLE I An undrawn yarn of 540 denier filaments of polyethylene terephthalate was drawn on a draw frame having a feed roll heated to 95 C. and a hot plate heated to 170 C., at a draw ratio of 3.62:1. The draw speed was 1200 feet per minute. The draw roll was fitted at the rear with a flange carrying ten hardened and polished, inch diameter, 2-grooved, steel pins the free ends of which described a circle approximately 6 inches diameter around the 4 inches diameter draw roll. The pins were mounted as shown in the accompanying drawing and were inclined at 30 to the side of the flange on which they were mounted.

It was observed when the draw roll was rotated slowly by hand (as was also observed at the draw speed by means of stroboscopic illumination) that each pin caused the yarn to split into small groups of filaments which were momentarily delayed by the grooves from disengaging with the pin before the next pin made contact with the yarn.

A guide for the yarn was situated 5 inches away from the point where the pins engaged the yarn. After passing round the draw roll for approximately two-thirds of a turn, the yarn was influenced by a guide which ensured that the yarn was only acted on once by the pins. The yarn passed three times round a separator roll and the draw roll before being wound up on a side-wind mechanism.

The resulting yarn was found to be free of broken and/ or loopy filaments and had an average coherency factor of 76 counts per 20 metres length. The same yarn drawn under identical conditions but in the absence of the defiector pins had a coherency factor of 26 counts per 20 metres length.

EXAMPLE II The flange and pins used in Example I were removed from the draw roll of the draw frame, and another roll of 5 inches diameter was mounted between the draw roll and the side-wind mechanism.

A flange 8.5 inches in diameter was mounted on this roll, and carried twelve, polished steel pins of inch diameter angled thereto at 30 as in the case of Example I. Each pin had four V-shaped grooves therein, 0.01 inch wide and 0.003 inch deep, with 45 walls, and spaced at a centre-to-centre distance of 0.025 inch along the axis of the pin in the vicinity of the free end thereof. The ends of the pins described of circle of 6 /2 inches diameter round the roll of 5 inches diameter. The surface speed of this roll was brought up to 2000 feet/minute which was the same as that of the draw roll.

An undrawn yarn of 540 denier, 30 filaments of polyethylene terephthalate was then drawn on the draw frame at a draw ratio of 3.62:1, and, after drawing, passed from the draw roll to the flanged roll under a tension of 130 grams before passing to the side-wind mechanism. A fixed guide positioned 4 inches before the point of contact of the yarn with the pins controlled the direction of the yarn approach and limited the length of vibrating yarn.

The yarn processed according to this example had a coherency factor of counts per 20 metres length. A control yarn was processed on the apparatus, but with the flange and pins removed, and was found to have a coherency factor of only '25 counts per 20 metres length.

EXAMPLE. III

Using the drawing apparatus of Example II, the surface speed of the flanged roll was reduced so that the yarn tension was only 16 grams. Under these conditions, an undrawn yarn of 540 denier, 30 filaments of polyethylene terephthalate was then drawn and intermingled as in Example II. The resulting yarn had a coherency factor of 29 counts per 20 metres length. By increasing the surface speed of the flanged roll the yarn tension was restored to grams, resulting in an increase of coherency factor to 90 counts per 20 metres length.

EXAMPLE IV An idler roll of 2 inches diameter having a rear flange 5 inches in diameter mounted thereon was mounted in close relationship to the draw roll of a draw frame. The

flange carried six pins, each having four grooves, oriented as in the previous examples. The flanged roll was used as a separator roll and carried a number of turns of drawn yarn in conjunction with the draw roll. In order to isolate the drawing zone from the deflecting action of the pins, two turns of yarn (of the type used in the previous examples) were taken around a separate small idler roll before passing the yarn round the flanged roll. 'Of five turns of the yarn taken round the flanged roll and the draw roll, only the first turn was subjected to the action of the pins. Guides were used to determine the displacement of the yarn by the pins and to ensure that the pins only deflected the first turn of the yarn.

The yarn was drawn at the draw ratio of 3.62:1 and had a coherency factor of 113 counts per 20 metres length.

EXAMPLE V An undrawn polyethylene terephthalate yarn of 900 denier, 180 filaments was drawn and interlaced according to Example IV, the resulting yarn had a coherency factor of 143 counts per 20 metres length.

EXAMPLE VI Nylon 6.6 yarn was drawn to a yarn of 1040 denier, 68 filaments between feed and draw rolls, using an unheated steel rod of /8 inch diameter to control the draw point. The draw speed was 1000 feet per minute and the yarn was preheated by having the feed roll heated to 80 C. After being drawn, the yarn was passed over the flanged roll described in Example II before being collected on the side-wind mechanism. The surface speed of the flanged roll was adjusted to produce a tension in the yarn of 950 grams. The resulting yarn was found to have a coherency factor of 136 counts per 20 metres length.

EXAMPLE VII A Rieter 15/5 nylon drawtwister was modified by mounting an auxiliary separator roll 6 inches below the centre ofthe draw roll. An oscillator disc was mounted on the auxiliary separator roll and carried two Sintox pins of 4 inch diameter set 1% inches diametrically apart. The oscillator was driven by taking the first two draw roll yarn turns around it. The penultimate drawroll yarn turn engaged a A inch diameter stationary pin of silver steel mounted in the yarn path between the draw roll and the auxiliary separator roll. The pin had a plurality of grooves therein and was arranged relative to the yarn such that the oscillator caused the yarn to traverse to and fro across the pin surface.

Using the above apparatus, an undrawn nylon 6.6 yarn of 205 denier, 34 filaments was drawn using a draw speed of 3308 feet per minute. The twist level was maintained at 0.25 turn per inch and the balloon tension was adjusted to 0.1 gram per denier. The resulting yarn was found to have a coherency factor of 94 counts per 20 metres length.

A comparison of coherent yarns processed according to the present invention and coherent yarns processed by air intermingling methods has shown that in general the coherent yarn produced by the former method, exhibits a more uniform intermingling of the filaments. Furthermore, coherent polyethylene terephthalate yarns produced by the method of the present invention when processed on a bulking machine and knitted into fabric and dyed, exhibited a lower variability in dye up-take than air intermingled polyethylene terephthalate yarns processed in the same manner.

Advantages of the present invention are that it provides a simple and cheap method of producing coherent yarns, and it does not have associated therewith the excessive noise levels inherent in the use of most air methods for intermingling.

What is claimed is:

1. A method of producing a continuous, multifilament, coherent yarn, comprising subjecting a longitudinally moving bundle of substantially parallel filaments, maintained under tension, to the action of a deflecting member having a free end and exhibiting a surface which contacts the yarn and which intermittently deflects the bundle of filaments from its path of travel, and randomly releasing the filaments from the deflecting member after each deflection by effecting relative transverse movement between the moving filaments and the deflecting member so that the filaments ride along the surface and fall from the free end of the member and so that the tension in the filaments causes them to vibrate and become individually and collectively intertwined and entangled to form a coherent structure.

2. A method according to claim 1, wherein the bundle of filaments is deflected by moving the deflecting member across the path of travel thereof.

3. A method according to claim 1, wherein the bundle of filaments is deflected by moving the bundle to and fro transversely to its mean path of travel across a stationary deflecting member.

References Cited UNITED STATES PATENTS 3,047,932 8/1962 Pittman et a1. 28-1 3,269,105 8/1966 Eldridge et a1. 28-72 X 3,284,871 11/1966 Yano et a1 2872 3,304,593 2/1967 Burklund 2872 X 3,328,863 7/1967 Cobb et al 28-72 X LOUIS K. RIMRODT, Primary Examiner 

